This section provides background information related to the present disclosure which is not necessarily prior art. Gas fired heating appliances use a source of gas and a source of air that are mixed and transmitted to a burner where an igniter initiates combustion. However, the ratio of gas to air in the gas/air mixture is essential to maintaining good combustion and keeping efficiency within an acceptable range. While a flame becomes more conductive as the ratio of the air/fuel mixture approaches near-stoichiometric conditions, attempts to use ionic flame monitoring to maintain a peak flame rod current have resulted in incomplete combustion due to shortage of primary air, as disclosed in U.S. Pat. No. 6,356,199 to Niziolek. Moreover, the sensor supplying the ionization signal ages during burner operation as a result of dirt deposited on the sensor and chemical decomposition, which makes the ionization sensor signal no longer reliable since the electrical behavior of the sensor changes, as disclosed in U.S. Pat. No. 6,783,355 to Blaauwwiekel. Thus, ionic flame monitoring equipment is only reliable for indicating a flame presence, and does not provide reliable feedback over time about the quality of the flame.